Temperature estimation, temperature drift compensation method and ultrasonic wave sensing device

Abstract

This application provides a temperature estimation and temperature drift compensation method and an ultrasonic sensing device. The method includes: upon receiving a temperature estimation trigger command, obtaining a transient temperature measured by a temperature sensor; obtaining a first flight time corresponding to the transient temperature based on the transient temperature and a preset correspondence between temperature and flight time; determining multiple second flight times within a preset range of the first flight time, the preset range being determined based on the transient temperature; configuring the ultrasonic sensor according to the multiple second flight times to obtain multiple ultrasonic images acquired by the ultrasonic sensor; obtaining a third flight time corresponding to the maximum value of the image quality parameter among the multiple ultrasonic images; and using the equivalent temperature corresponding to the third flight time as the estimated temperature of the ultrasonic sensing device according to the correspondence between temperature and flight time. This application embodiment can accurately estimate the temperature of the ultrasonic sensing device, improving the recognition effect of target objects.

Description

Technical Field

[0001] This application relates to the field of ultrasonic sensing, and more particularly to a method for temperature estimation and temperature drift compensation, and an ultrasonic sensing device. Background Technology

[0002] Ultrasonic unlocking solutions are gradually becoming a mainstream solution in the unlocking field due to their advantages such as fast unlocking speed, high accuracy, simple data entry, and wide applicability. Devices using ultrasonic unlocking solutions, such as mobile phones, wearable devices, electronic locks, tablets, and computers, are generally referred to as ultrasonic sensing devices. These devices typically have an ultrasonic sensor installed inside their casing. The ultrasonic sensor emits and receives ultrasonic waves to identify the target object (e.g., a fingerprint) and unlock the device.

[0003] Because ultrasound is a mechanical wave, its time of flight (TOF, i.e., the time interval between transmission and reception) and signal strength are greatly affected by temperature. Temperature changes can impact the effectiveness of target object recognition. However, if the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor in the area where the sensor is located) cannot be accurately assessed in static or dynamically changing temperature scenarios, it will severely affect the target object recognition performance, thus failing to provide a satisfactory unlocking experience for the user.

[0004] Therefore, how to accurately estimate the temperature of ultrasonic sensing devices has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of this application provide a temperature estimation and temperature drift compensation method and an ultrasonic sensing device, which can accurately estimate the temperature of the ultrasonic sensing device and improve the recognition effect of the target object.

[0006] According to a first aspect of the present application, a temperature estimation method is provided, applied to an ultrasonic sensing device. The ultrasonic sensing device includes an ultrasonic sensor and a temperature sensor disposed inside a housing of the ultrasonic sensing device. The method includes: if a temperature estimation trigger command is received, obtaining a transient temperature measured by the temperature sensor; obtaining a first flight time corresponding to the transient temperature based on the transient temperature and a preset correspondence between temperature and flight time; determining a plurality of second flight times within a preset range of the first flight time, the preset range being determined based on the transient temperature; configuring the ultrasonic sensor according to the plurality of second flight times to obtain a plurality of ultrasonic images acquired by the ultrasonic sensor; obtaining a third flight time corresponding to the maximum value of the image quality parameter in the plurality of ultrasonic images; and using the equivalent temperature corresponding to the third flight time as the estimated temperature of the ultrasonic sensing device according to the correspondence between temperature and flight time.

[0007] According to a second aspect of the present application, a temperature drift compensation method is provided, applied to an ultrasonic sensing device. The ultrasonic sensing device includes an ultrasonic sensor and a temperature sensor disposed inside the housing of the ultrasonic sensing device. The method includes: if a temperature estimation trigger command is received, obtaining a transient temperature measured by the temperature sensor; obtaining a first flight time corresponding to the transient temperature based on the transient temperature and a preset correspondence between temperature and flight time; determining a plurality of second flight times within a preset range of the first flight time, the preset range being determined based on the transient temperature; configuring the ultrasonic sensor according to the plurality of second flight times to obtain a plurality of ultrasonic images acquired by the ultrasonic sensor; obtaining a third flight time corresponding to the maximum value of the image quality parameter in the plurality of ultrasonic images, and using the equivalent temperature corresponding to the third flight time as the estimated temperature of the ultrasonic sensing device according to the correspondence between temperature and flight time; obtaining a background signal value corresponding to the estimated temperature according to a preset correspondence between temperature and background signal value, the background signal value being used to characterize the signal received by the ultrasonic sensor when no target object touches the housing.

[0008] According to a third aspect of the present application, an ultrasonic sensing device is provided, comprising: an ultrasonic sensor and a temperature sensor disposed inside a housing of the ultrasonic sensing device, and a processor, wherein the temperature sensor is disposed adjacent to the ultrasonic sensor or multiple temperature sensors are disposed between the ultrasonic sensor and the inner surface of the housing of the ultrasonic sensing device, and the processor is used to execute the method described in the first or second aspect above.

[0009] According to the temperature estimation, temperature drift compensation method, and ultrasonic sensing device provided in this application embodiment, when a temperature estimation trigger command is received, the transient temperature measured by the temperature sensor is obtained. Based on the transient temperature and a preset correspondence between temperature and flight time, a first flight time corresponding to the transient temperature is obtained, and multiple second flight times within a preset range of the first flight time are determined. An ultrasonic sensor is configured according to the multiple second flight times to obtain multiple ultrasonic images acquired by the ultrasonic sensor. In this application embodiment, the equivalent temperature corresponding to the third flight time corresponding to the maximum value of the image quality parameters of the multiple ultrasonic images is used as the estimated temperature of the ultrasonic sensing device. The estimated temperature obtained in this application embodiment is closer to the actual temperature of the ultrasonic sensing device's housing (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located). The obtained estimated temperature can be used to avoid target object recognition errors caused by a large difference between the transient temperature and the actual temperature of the ultrasonic sensing device's housing (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located), improving the accuracy of target object recognition and thus providing a satisfactory unlocking experience for the user. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0011] Figure 1 , Figure 2 This is a schematic diagram of the structure of an ultrasonic sensing device according to an embodiment of this application;

[0012] Figure 3 This is a temperature diagram of an ultrasonic sensing device according to an embodiment of this application.

[0013] Figure 4 This is a flowchart of a temperature estimation method in one embodiment of this application;

[0014] Figure 5 This is a schematic diagram illustrating the relationship between temperature and flight time in a temperature estimation method according to an embodiment of this application;

[0015] Figure 6 This is a schematic diagram of the fitting curve of the average background signal of the temperature estimation method in one embodiment of this application;

[0016] Figure 7 This is a flowchart of a temperature estimation method in another embodiment of this application;

[0017] Figure 8This is a schematic diagram illustrating transient temperature correction in another embodiment of this application;

[0018] Figure 9 This is a flowchart of another embodiment of the temperature drift compensation method of this application;

[0019] Figure 10 This is a flowchart of another embodiment of the temperature drift compensation method of this application;

[0020] Figure 11 a-j is a fingerprint recognition schematic diagram in another embodiment of this application;

[0021] Figure 12 , Figure 13 This is a schematic diagram of the structure of an ultrasonic sensing device in another embodiment of this application. Detailed Implementation

[0022] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings. For ease of explanation, the same reference numerals denote the same components in the embodiments of this application, and for brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative examples and should not constitute any limitation on this application.

[0023] It should be noted that, without conflict, the various embodiments and / or technical features described in this application can be arbitrarily combined with each other, and the resulting technical solutions should also fall within the protection scope of this application.

[0024] It should be understood that the specific examples in the embodiments of this application are only for the purpose of helping those skilled in the art to better understand the embodiments of this application, and are not intended to limit the scope of the embodiments of this application.

[0025] It should also be understood that, in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0026] It should also be understood that the terminology used in the embodiments of this application and the appended claims is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. For example, the singular forms "a," "the," and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0027] As used herein, terms such as “first,” “second,” and “third” describe various components, parts, areas, layers, and / or sections, but such components, parts, areas, layers, and / or sections should not be limited by such terms. These terms are used only to distinguish one component, part, area, layer, or section from another. For example, the use of terms such as “first,” “second,” and “third” herein does not imply sequence or order unless explicitly indicated by the context.

[0028] Furthermore, for ease of description, spatial relative terms such as “below,” “under,” “above,” “upper,” and similar terms may be used herein to describe the relationship of one component or member to another component or member illustrated in the figures. In addition to the orientations depicted in the figures, spatial relative terms are intended to cover different orientations of the device during use or operation. The device may be oriented in other ways (rotated 90 degrees or otherwise) and therefore the spatial relative descriptors used herein may be interpreted in the same way.

[0029] See Figure 1 and Figure 2 In typical ultrasonic sensing devices, during the acquisition of biometric images (using fingerprint images as an example for ease of understanding), the transmitting unit Tx (not shown in the figure) of the ultrasonic sensor 11 inside the device emits ultrasonic signals. These signals pass through the housing 2 of the ultrasonic sensor (i.e., a plate of a certain thickness that allows ultrasonic waves to pass through, such as an adhesive layer or screen) and reach the outer surface of the housing. They are then reflected by the target object 3 (e.g., a finger) and return to the receiving unit Rx (not shown in the figure) of the ultrasonic sensor after passing through the housing 2. For ease of explanation, a finger will be used as the target object in the following explanation. Due to the difference in ultrasonic reflectivity between the valleys and ridges of the finger, fingerprint information is present in the reflected ultrasonic signal. The signal acquired by the ultrasonic sensor 11 at this time is the target object signal value (Raw value). The target object signal value (Raw value) received by the ultrasonic sensor 11 also contains the background signal value (Base value) reflected by the housing 2. When no finger touches the housing 2, the signal received by the ultrasonic sensor 11 is called the background signal value (Base value). The target object image, i.e., the fingerprint image, can be obtained by subtracting the background signal value (Base value) from the target object signal value (Raw value).

[0030] Typical ultrasonic sensing devices obtain transient temperature through a temperature sensor 12 located near the ultrasonic sensor 11, and use this transient temperature as the actual temperature of the ultrasonic sensing device. Because the ultrasonic sensing device housing 2 has a certain thickness (illustrated as a screen stack in the figure), even in a static temperature scenario, the transient temperature obtained by the temperature sensor 12 is not equal to the actual temperature of the ultrasonic sensing device housing (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located). Especially in scenarios with dynamic temperature changes, the temperature difference between the outer and inner surfaces of the ultrasonic sensing device housing 2 is significant, resulting in a large difference between the transient temperature and the actual temperature of the ultrasonic sensing device housing (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located).

[0031] For example, in a scenario of dynamic temperature changes, the actual temperature of the housing of the ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located) is described. See [link to documentation]. Figure 3 When the ambient temperature changes, such as when the ultrasonic sensor is moved from an environment of temperature T1 to an environment of temperature T2, or when a finger at temperature T2 touches the ultrasonic sensor at temperature T1, the temperature of the ultrasonic sensor will be affected, gradually changing from temperature T1 to temperature T2. During the heat transfer process, the outer and inner surfaces of the ultrasonic sensor housing 2, which are in contact with the environment or the finger, have different temperatures, neither of which can characterize the actual temperature T3 of the ultrasonic sensor housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located).

[0032] Therefore, the transient temperature obtained by the ultrasonic sensing device 2 through the temperature sensor 12 deviates significantly from the actual temperature of the ultrasonic sensing device 2's housing (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located). If the background signal value (Base value) of the ultrasonic sensing device is obtained using the transient temperature, or if the background signal value (Base value) of the ultrasonic sensing device is obtained by combining the transient temperature with historical background signal values ​​(Base values), it will deviate from the actual value of the ultrasonic sensing device's background signal value (Base value), thereby reducing the signal-to-noise ratio of the target object image (i.e., the difference between the target object signal value (Raw value) and the background signal value (Base value)).

[0033] This application provides a method for estimating the actual temperature of the housing of an ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located). This application can accurately estimate the actual temperature of the housing of an ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located) under static temperature scenarios and under scenarios with dynamic temperature changes.

[0034] See Figure 1 and Figure 2 The ultrasonic sensing device used in this application embodiment includes an ultrasonic sensor 11 and a temperature sensor 12 disposed inside the ultrasonic sensing device housing 2. The temperature sensor 12 can be disposed below the ultrasonic sensing device housing 2 and can be disposed adjacent to the ultrasonic sensor 11 to detect the temperature of the ultrasonic sensor 11.

[0035] Specifically, when the target object 3 touches the surface of the housing 2 of the ultrasonic sensor, the ultrasonic waves emitted by the ultrasonic sensor 11 pass through the housing 2 and reach the outer surface of the housing 2. After being reflected by the target object 3, they pass back through the housing 2 to the ultrasonic sensor 11. The ultrasonic sensor 11 obtains the target object signal value (Raw value) from the received ultrasonic signal and then obtains the pre-stored background signal value (Base value). By subtracting the background signal value (Base value) from the target object signal value (Raw value), the image of the target object can be obtained.

[0036] The temperature estimation method in this application provides a more accurate estimate of the temperature of the ultrasonic sensor housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located). This allows the acquisition of the corresponding background signal value (Base value) based on the estimated temperature, thereby obtaining a more accurate image of the target object.

[0037] See Figure 4 This application provides a temperature estimation method, comprising:

[0038] S1. If a temperature estimation trigger command is received, the transient temperature measured by the temperature sensor is obtained.

[0039] In a specific implementation of Embodiment 1 of this application, the temperature estimation trigger instruction includes:

[0040] The command for the target object to touch the surface, where the surface is the outer surface of the ultrasonic sensor housing corresponding to the area where the ultrasonic sensor is located; or,

[0041] The timer satisfies the instruction of the timing value, which represents the time when the temperature estimation operation of the ultrasonic sensor is awakened.

[0042] In this embodiment of the application, when the target object touches (e.g., presses or lifts a finger) the surface of the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located, the ultrasonic sensing device activates the temperature sensor to measure the transient temperature.

[0043] In this embodiment of the application, the ultrasonic sensor can also start the temperature sensor to measure the transient temperature when the timer meets the time value at which the temperature estimation operation is awakened (for example, when the ultrasonic sensor in sleep mode reaches a preset time point).

[0044] The temperature estimation trigger command in this embodiment can achieve transient temperature acquisition when the conditions for transient temperature acquisition are met. That is, when the target object touches the object or the timer reaches its timing value, the temperature sensor is activated to capture the transient temperature for subsequent temperature estimation. This embodiment avoids the power consumption caused by the temperature sensor being constantly in operation.

[0045] S2. Based on the transient temperature and the preset correspondence between temperature and flight time, obtain the first flight time corresponding to the transient temperature, and determine multiple second flight times within a preset range of the first flight time. The preset range is determined based on the transient temperature.

[0046] Specifically, the correspondence between temperature and flight time in the embodiments of this application can be based on historical data, and this correspondence can be pre-stored in the ultrasonic sensing device.

[0047] For example, the correspondence between temperature and flight time can be shown in Table 1.

[0048] Table 1

[0049] temperature Flight time T4 F1 T5 F2 T6 F3 …… ……

[0050] For example, the correspondence between temperature and flight time is as follows: Figure 5 The curves show the correspondence between temperatures T4, T5, and T6 and flight times F1, F2, and F3, which is a one-to-one correspondence between temperature and flight time.

[0051] In this embodiment, if the transient temperature is T4, the corresponding first flight time is F1. Multiple second flight times are determined within a preset range of the first flight time F1, and this preset range can be determined by the transient temperature T4.

[0052] Specifically, those skilled in the art determine multiple second flight times within a preset range of the first flight time F1 based on experience and the accuracy requirements for temperature estimation of the ultrasonic sensing device.

[0053] If the transient temperature T4 is high, it means that the inner surface temperature of the ultrasonic sensor housing is high, the temperature difference between the inner and outer surfaces of the ultrasonic sensor housing is small, and the preset range of the first flight time F1 is small. If the transient temperature T4 is low, it means that the inner surface temperature of the ultrasonic sensor housing is low, the temperature difference between the inner and outer surfaces of the ultrasonic sensor housing is large, and the preset range of the first flight time F1 is large.

[0054] S3. Configure the ultrasonic sensor according to multiple second flight times to obtain multiple ultrasonic images acquired by the ultrasonic sensor.

[0055] According to the embodiments of this application, the transmission parameters and reception parameters of the transmitting unit Tx and receiving unit Rx of the ultrasonic sensor are configured based on multiple second flight times, thereby obtaining multiple ultrasonic images acquired by the ultrasonic sensor.

[0056] Specifically, in this embodiment, the transmitting and receiving units of the ultrasonic sensor are configured according to multiple second time-of-flight times to obtain multiple ultrasonic images corresponding to the multiple second time-of-flight times. The multiple ultrasonic images in this embodiment have their own image quality parameters. For example, M ultrasonic images correspond to M image quality parameters, where M is a positive integer greater than 2.

[0057] S4. Obtain the third flight time corresponding to the maximum value of the image quality parameters in multiple ultrasonic images, and use the equivalent temperature corresponding to the third flight time as the estimated temperature of the ultrasonic sensing device based on the correspondence between temperature and flight time.

[0058] This application embodiment obtains the third flight time corresponding to the maximum value of image quality parameters in multiple ultrasonic images, according to Table 1 above or... Figure 5 The correspondence between temperature and flight time in the data is used to obtain the equivalent temperature corresponding to the third flight time. Since the third flight time is the flight time corresponding to the maximum value of the image quality parameter in multiple ultrasonic images, the temperature corresponding to the third flight time is closest to the actual temperature of the housing of the ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located). Therefore, this embodiment of the application uses the equivalent temperature corresponding to the third flight time as the estimated temperature to obtain an estimated temperature that is closer to the actual temperature of the housing of the ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located).

[0059] In another specific implementation of this application, the maximum value of the image quality parameters of multiple ultrasound images includes:

[0060] The largest value among the image quality parameters of multiple ultrasound images is selected as the maximum value of the image quality parameter.

[0061] If the image quality parameters of multiple ultrasound images exist in a discrete state, the maximum value among them is directly selected as the maximum value of the image quality parameter.

[0062] In this embodiment, the maximum value of the image quality parameters of multiple discrete ultrasonic images is directly selected as the maximum value of the image quality parameters without further data processing, and the maximum value of the image quality parameters of multiple ultrasonic images can be obtained quickly and easily.

[0063] In another specific implementation of this application, the image quality parameters of multiple ultrasound images are fitted into a curve, and the peak point of the curve is obtained as the maximum value of the image quality parameter.

[0064] In this application embodiment, the image quality parameters of multiple ultrasonic images are fitted into a curve, thereby obtaining the peak point of the curve. This point can more accurately reflect the image quality parameters of the ultrasonic image with the best image quality, thereby obtaining the flight time corresponding to the ultrasonic image with the best image quality as the third flight time.

[0065] This application embodiment utilizes curve fitting to obtain the image quality parameters of the ultrasound images corresponding to the peak points among the image quality parameters of multiple ultrasound images, which can accurately obtain the maximum value of the image quality parameters of multiple ultrasound images.

[0066] Image quality parameters include one of the following: signal-to-noise ratio of the ultrasound image, value of at least one pixel of the ultrasound image, weighted value of at least one pixel of the ultrasound image, average value of multiple pixel values ​​of the ultrasound image, average signal strength of the ultrasound image, and average background signal of the ultrasound image.

[0067] For example, see Figure 6 In this embodiment, the average background signal of multiple ultrasound images is used as the image quality parameter. If the average background signal of multiple ultrasound images is fitted to curve one, the peak point of curve one is obtained as the maximum value of the image quality parameter, and the flight time corresponding to the maximum value of the image quality parameter is obtained as the third flight time Fy1. If the average background signal of multiple ultrasound images is fitted to curve two, the peak point of curve two is obtained as the maximum value of the image quality parameter, and the flight time corresponding to the maximum value of the image quality parameter is obtained as the third flight time Fy2.

[0068] The estimated temperature obtained in this embodiment is closer to the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located). This estimated temperature allows the acquisition of a background signal value corresponding to that temperature. This background signal value, rather than the initial background signal value of the ultrasonic sensor at the time of manufacture, is then used to calculate the target object image. This avoids target object recognition errors caused by significant differences between transient temperature and the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located), improving the accuracy of target object recognition and ultimately providing a satisfactory unlocking experience for the user.

[0069] In a static temperature scenario, the estimated temperature obtained in this embodiment can be used to correct the transient temperature measured by the temperature sensor. See also Figure 7 The method also includes:

[0070] S5. Correct the transient temperature measured by the temperature sensor based on the estimated temperature.

[0071] Specifically, see Figure 8 Since there is a temperature difference between the transient temperature measured by the temperature sensor and the actual temperature of the housing of the ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located), the estimated temperature obtained in this application embodiment can be used to correct the transient temperature measured by the temperature sensor, thereby obtaining an estimated temperature that is closer to the actual temperature of the housing of the ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located).

[0072] This application also provides a temperature drift compensation method, applied to... Figure 1 and Figure 2 The ultrasonic sensing device shown.

[0073] See Figure 9 The present application provides a temperature drift compensation method, comprising:

[0074] Q1. If a temperature estimation trigger command is received, the transient temperature measured by the temperature sensor is obtained.

[0075] In a specific implementation of Embodiment 1 of this application, the temperature estimation trigger instruction includes:

[0076] The command for the target object to touch the surface, where the surface is the outer surface of the ultrasonic sensor housing corresponding to the area where the ultrasonic sensor is located; or,

[0077] The timer satisfies the instruction of the timing value, which represents the time when the temperature estimation operation of the ultrasonic sensor is awakened.

[0078] In this embodiment of the application, when the target object touches (e.g., presses or lifts a finger) the surface of the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located, the ultrasonic sensing device activates the temperature sensor to measure the transient temperature.

[0079] In this embodiment of the application, the ultrasonic sensor can also start the temperature sensor to measure the transient temperature when the timer meets the time value at which the temperature estimation operation is awakened (for example, when the ultrasonic sensor in sleep mode reaches a preset time point).

[0080] The temperature estimation trigger command in this embodiment can acquire transient temperature when the conditions for transient temperature acquisition are met. Specifically, it activates the temperature sensor when a target object touches the sensor or when a timer reaches its set value, capturing the transient temperature for subsequent temperature estimation. This embodiment avoids the power consumption caused by the temperature sensor being constantly operational.

[0081] Q2. Based on the transient temperature and the preset correspondence between temperature and flight time, obtain the first flight time corresponding to the transient temperature, and determine multiple second flight times within a preset range of the first flight time. The preset range is determined based on the transient temperature.

[0082] Specifically, in the embodiments of this application, the correspondence between temperature and flight time is obtained based on historical data and pre-stored in the ultrasonic sensing device.

[0083] For example, the correspondence between temperature and flight time is shown in Table 1.

[0084] Table 1

[0085] temperature Flight time T4 F1 T5 F2 T6 F3 …… ……

[0086] For example, the correspondence between temperature and flight time is as follows: Figure 5 The curves show the correspondence between temperatures T4, T5, and T6 and flight times F1, F2, and F3.

[0087] In this embodiment, if the transient temperature is T4, the corresponding first flight time is F1. Multiple second flight times are determined within a preset range of the first flight time F1, and this preset range is determined by the transient temperature T4.

[0088] Specifically, those skilled in the art determine multiple second flight times within a preset range of the first flight time F1 based on experience and the accuracy requirements for temperature estimation of the ultrasonic sensing device.

[0089] If the transient temperature T4 is high, it means that the inner surface temperature of the ultrasonic sensor housing is high, and the temperature difference between the inner and outer surfaces of the ultrasonic sensor housing is small. Therefore, the preset range for the first flight time F1 can be set to a smaller value. If the transient temperature T4 is low, it means that the inner surface temperature of the ultrasonic sensor housing is low, and the temperature difference between the inner and outer surfaces of the ultrasonic sensor housing is large. Therefore, the preset range for the first flight time F1 can be larger.

[0090] Q3. Configure the ultrasonic sensor according to multiple second flight times to obtain multiple ultrasonic images acquired by the ultrasonic sensor.

[0091] According to the embodiments of this application, the transmission parameters and reception parameters of the transmitting unit Tx and receiving unit Rx of the ultrasonic sensor are configured based on multiple second flight times, thereby obtaining multiple ultrasonic images acquired by the ultrasonic sensor.

[0092] Specifically, in this embodiment, the transmitting and receiving units of the ultrasonic sensor are configured according to multiple second time-of-flight times to obtain multiple ultrasonic images corresponding to the multiple second time-of-flight times. The multiple ultrasonic images in this embodiment have their own image quality parameters. For example, M ultrasonic images correspond to M image quality parameters, where M is a positive integer greater than 2.

[0093] Q4. Obtain the third flight time corresponding to the maximum value of the image quality parameters in multiple ultrasonic images, and use the equivalent temperature corresponding to the third flight time as the estimated temperature of the ultrasonic sensing device based on the correspondence between temperature and flight time.

[0094] This application embodiment obtains the third flight time corresponding to the maximum value of image quality parameters in multiple ultrasonic images, according to Table 1 above or... Figure 5 The correspondence between temperature and flight time in the data is used to obtain the equivalent temperature corresponding to the third flight time. Since the third flight time is the flight time corresponding to the maximum value of the image quality parameter in multiple ultrasonic images, the temperature corresponding to the third flight time is closest to the actual temperature of the housing of the ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located). Therefore, this embodiment of the application uses the equivalent temperature corresponding to the third flight time as the estimated temperature to obtain an estimated temperature that is closer to the actual temperature of the housing of the ultrasonic sensing device (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located).

[0095] In another specific implementation of this application, the maximum value of the image quality parameters of multiple ultrasound images includes:

[0096] The largest value among the image quality parameters of multiple ultrasound images is selected as the maximum value of the image quality parameter.

[0097] If the image quality parameters of multiple ultrasound images exist in a discrete state, the maximum value among them is directly selected as the maximum value of the image quality parameter.

[0098] In this embodiment, the maximum value of the image quality parameters of multiple discrete ultrasonic images is directly selected as the maximum value of the image quality parameters without further data processing, and the maximum value of the image quality parameters of multiple ultrasonic images can be obtained quickly and easily.

[0099] In another specific implementation of this application, the image quality parameters of multiple ultrasound images are fitted into a curve, and the peak point of the curve is obtained as the maximum value of the image quality parameter.

[0100] In this application embodiment, the image quality parameters of multiple ultrasonic images are fitted into a curve, thereby obtaining the peak point of the curve. This point can more accurately reflect the image quality parameters of the ultrasonic image with the best image quality, thereby obtaining the flight time corresponding to the ultrasonic image with the best image quality as the third flight time.

[0101] This application embodiment utilizes curve fitting to obtain the image quality parameters of the ultrasound images corresponding to the peak points among the image quality parameters of multiple ultrasound images, which can accurately obtain the maximum value of the image quality parameters of multiple ultrasound images.

[0102] The image quality parameters include one of the following:

[0103] The signal-to-noise ratio of the ultrasound image, the value of at least one pixel in the ultrasound image, the weighted value of at least one pixel in the ultrasound image, the average value of multiple pixel values ​​in the ultrasound image, the average signal intensity of the ultrasound image, and the average background signal of the ultrasound image.

[0104] For example, see Figure 6 In this embodiment, the average background signal of multiple ultrasound images is used as the image quality parameter. If the average background signal of multiple ultrasound images is fitted to curve one, the peak point of curve one is obtained as the maximum value of the image quality parameter, and the flight time corresponding to the maximum value of the image quality parameter is obtained as the third flight time Fy1. If the average background signal of multiple ultrasound images is fitted to curve two, the peak point of curve two is obtained as the maximum value of the image quality parameter, and the flight time corresponding to the maximum value of the image quality parameter is obtained as the third flight time Fy2.

[0105] Q5. Based on the preset correspondence between temperature and background signal value, obtain the background signal value corresponding to the estimated temperature. The background signal value is used to characterize the signal received by the ultrasonic sensor when no target object touches the shell.

[0106] In this embodiment, the correspondence between temperature and background signal values ​​is obtained based on historical data and saved to the ultrasonic sensing device.

[0107] For example, the correspondence between temperature and background signal values ​​is shown in Table 2.

[0108] Table 2

[0109] temperature Background signal value T7 B1 T8 B2 T9 B3 …… ……

[0110] If the estimated temperature is T7, then the background signal value is obtained as B1 based on the correspondence between temperature and background signal value.

[0111] The estimated temperature in this embodiment is closer to the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located) than the transient temperature. Therefore, by using the estimated temperature and its correspondence with background signal values, the obtained background signal value is more accurate. The estimated temperature obtained in this embodiment is closer to the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located). This allows for the acquisition of a background signal value corresponding to the estimated temperature, which, instead of the initial background signal value when the ultrasonic sensor was manufactured, is used to calculate the target object image. This avoids the target object recognition error caused by a large difference between the transient temperature and the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located), improving the accuracy of target object recognition and providing a satisfactory unlocking experience for the user.

[0112] In another application scenario of this application embodiment, see [link to relevant documentation]. Figure 10 The methods also include:

[0113] Q6. If a background signal value acquisition instruction is received and the background signal value update condition is met, the background signal value corresponding to the estimated temperature will be updated to the background signal value database.

[0114] In this embodiment, if the received instruction is a background signal value acquisition instruction, that is, the ultrasonic sensing device of this application needs to acquire a background signal value. In this embodiment, when obtaining the background signal value corresponding to the estimated temperature in step Q5, it is necessary to further determine whether the background signal value update condition is met. If the background signal value update condition is met, the background signal value corresponding to the estimated temperature is updated to the background signal value database.

[0115] Specifically, the background signal value update conditions include:

[0116] Q7. If a fingerprint acquisition command is received, the ultrasonic sensor obtains the target object signal value and subtracts the background signal value from the target object signal value to obtain the target object image.

[0117] In this embodiment of the application, if a fingerprint acquisition command is received, the ultrasonic sensor obtains the target object signal value, subtracts the background signal value from the target object signal value, and obtains the target object image.

[0118] Specifically, see Figure 11 The target object images obtained by estimating the background signal value corresponding to the temperature using the embodiments of this application at different ambient temperatures are as follows: Figure 11 a- Figure 11 e; Images of the target object obtained using the background signal value corresponding to the transient temperature at different ambient temperatures are... Figure 11 f- Figure 11 j. Because the embodiments of this application use an estimated temperature that is closer to the actual temperature of the surface touched by the target object in the ultrasonic sensing device, a more accurate background signal value is obtained, thereby obtaining a clearer image of the target object. Figure 11 f- Figure 11 j is clearer.

[0119] The estimated temperature obtained in this embodiment is closer to the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located). This estimated temperature can be used to obtain a background signal value corresponding to that temperature. This background signal value, rather than the initial background signal value of the ultrasonic sensor when it leaves the factory, can then be used to calculate the target object image. This avoids target object recognition errors caused by large differences between transient temperature and the actual temperature of the ultrasonic sensor's housing (referring only to the housing of the ultrasonic sensor corresponding to the area where the ultrasonic sensor is located), improving the accuracy of target object recognition and thus providing a satisfactory unlocking experience for the user.

[0120] Corresponding to the above method, this application embodiment also provides an ultrasonic sensing device, including: an ultrasonic sensor and a temperature sensor disposed inside the housing of the ultrasonic sensing device, and a processor. The temperature sensor is disposed adjacent to the ultrasonic sensor, or multiple temperature sensors are disposed between the ultrasonic sensor and the inner surface of the housing of the ultrasonic sensing device. The processor is used to execute any of the above methods.

[0121] When the temperature sensor is placed between the ultrasonic sensor and the inner surface of the ultrasonic sensing device's housing, the temperature sensor can obtain more accurate transient temperature.

[0122] Further, see Figure 12 and Figure 13The temperature sensor consists of multiple sensors, which are positioned between the ultrasonic sensor and the inner surface of the ultrasonic sensing device's housing, thereby ensuring a more accurate transient temperature distribution.

[0123] The temperature sensor setting method used in this application embodiment can obtain more accurate transient temperature, thereby further reducing the difference between the estimated temperature and the actual temperature of the ultrasonic sensing device housing (referring only to the housing of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located), improving the accuracy of target object identification, and thus providing users with a satisfactory unlocking experience.

[0124] It should be noted that, depending on the implementation needs, the various components / steps described in the embodiments of this application can be broken down into more components / steps, or two or more components / steps or parts of the operation of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of this application.

[0125] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A temperature estimation method applied to an ultrasonic sensing device, the ultrasonic sensing device comprising: The method comprises the following steps: An ultrasonic sensor and a temperature sensor are arranged inside the ultrasonic sensor device shell, and the method comprises the following steps: If a temperature estimation trigger instruction is received, a transient temperature measured by the temperature sensor is obtained; According to the transient temperature and a preset temperature-time-of-flight correspondence relationship, a first time-of-flight corresponding to the transient temperature is obtained, a plurality of second time-of-flights within a preset range of the first time-of-flight are determined, and the preset range is determined according to the transient temperature; According to the plurality of second time-of-flights, the ultrasonic sensor is configured, and a plurality of ultrasonic images collected by the ultrasonic sensor are obtained; 2. The temperature estimation method according to claim 1, wherein A third time-of-flight corresponding to a maximum value of an image quality parameter of the plurality of ultrasonic images is obtained, and according to the temperature-time-of-flight correspondence relationship, an equivalent temperature corresponding to the third time-of-flight is taken as an estimated temperature of the ultrasonic sensor device. The temperature estimation trigger instruction comprises: An instruction that a target object touches a surface, and the surface is an outer surface of the shell of the ultrasonic sensor device corresponding to the region where the ultrasonic sensor is located; or 3. The temperature estimation method according to claim 1, wherein An instruction that a timer meets a timing value, and the timing value is a time value representing that a temperature estimation operation of the ultrasonic sensor device is awakened. The maximum value of the image quality parameter of the plurality of ultrasonic images comprises: A maximum value of the image quality parameter of the plurality of ultrasonic images is selected as the maximum value of the image quality parameter; or 4. The temperature estimation method according to claim 3, wherein The image quality parameters of the plurality of ultrasonic images are fitted into a curve, and a peak point of the curve is taken as the maximum value of the image quality parameter. The image quality parameter comprises one of the following:

5. The temperature estimation method of claim 1, wherein, A signal-to-noise ratio of an ultrasonic image, at least one pixel value of an ultrasonic image, a weighted value of a plurality of pixel values of an ultrasonic image, an average value of a plurality of pixel values of an ultrasonic image, an average value of signal intensity of an ultrasonic image, and an average value of background signal of an ultrasonic image. The method further comprises:

6. A method of temperature drift compensation applied to an ultrasonic sensing device, the ultrasonic sensing device comprising: According to the estimated temperature, the transient temperature measured by the temperature sensor is corrected. An ultrasonic sensor and a temperature sensor are arranged inside the ultrasonic sensor device shell, and the method comprises the following steps: If a temperature estimation trigger instruction is received, a transient temperature measured by the temperature sensor is obtained; According to the transient temperature and a preset temperature-time-of-flight correspondence relationship, a first time-of-flight corresponding to the transient temperature is obtained, a plurality of second time-of-flights within a preset range of the first time-of-flight are determined, and the preset range is determined according to the transient temperature; According to the plurality of second time-of-flights, the ultrasonic sensor is configured, and a plurality of ultrasonic images collected by the ultrasonic sensor are obtained; A third time-of-flight corresponding to a maximum value of an image quality parameter of the plurality of ultrasonic images is obtained, and according to the temperature-time-of-flight correspondence relationship, an equivalent temperature corresponding to the third time-of-flight is taken as an estimated temperature of the ultrasonic sensor device. According to a preset temperature-background signal value correspondence relationship, a background signal value corresponding to the estimated temperature is obtained, and the background signal value is used to represent a signal received by the ultrasonic sensor when no target object touches the shell.

7. The method of temperature drift compensation according to claim 6, wherein The method further comprises at least one of the following operations: If the background signal value acquisition instruction is received and the background signal value update condition is met, the estimated temperature corresponding background signal value is updated to the background signal value library; If the fingerprint collection instruction is received, the ultrasonic sensor obtains the target object signal value, and subtracts the background signal value from the target object signal value to obtain the target object image.

8. The method of temperature drift compensation according to claim 7, wherein The temperature estimation trigger instruction comprises: An instruction for the target object to touch the surface, which is the outer surface of the shell of the ultrasonic sensing device corresponding to the area where the ultrasonic sensor is located; or An instruction for the timer to meet the timing value, which is a time value representing the temperature estimation operation of the ultrasonic sensing device being awakened.

9. The method of temperature drift compensation according to claim 8, wherein, The maximum value of the image quality parameter of the plurality of ultrasonic images is: Selecting the maximum value in the image quality parameters of the plurality of ultrasonic images as the maximum value of the image quality parameter; or Fitting the image quality parameters of the plurality of ultrasonic images into a curve to obtain the peak point of the curve as the maximum value of the image quality parameter.

10. The method of temperature drift compensation according to claim 9, wherein, The image quality parameter comprises one of the following: The signal-to-noise ratio of the ultrasonic image, at least one pixel value of the ultrasonic image, a weighted value of at least one pixel value of the ultrasonic image, an average value of a plurality of pixel values of the ultrasonic image, a signal intensity average value of the ultrasonic image, and a background signal average value of the ultrasonic image.

11. An ultrasonic sensor device, comprising: The ultrasonic sensor and the temperature sensor are arranged inside the shell of the ultrasonic sensing device, and the processor is used to execute the method of any one of claims 1-10.

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